A Joseph asteroid is barreling towards -- eight times faster than a speeding bullet passing closer to lessen the satellites that broadcast is very program. But were still on a crash course here's ABC's Neal Karlinsky. On a sliding scale of things -- ruin your day you may want to put this one at the top of the list the asteroid with a not so catchy name. He's hurtling towards earth right now at a rate eight times faster than a speeding bullet. And -- -- will miss disaster won't be averted by much -- greased the Earth's atmosphere Friday afternoon at about 171000. Miles out. Remember all of those satellites out there. -- give us our global positioning. That tell -- iPhone where we are those are at 22000. Miles so this is actually going to pass between the earth. And the satellites that give us our direct TV every day. That's a close -- Hollywood loves this kind of thing exhibit eight Bruce Willis is Armageddon. But he's fourteen and others like you are no joke. Which is why a trio of big brains from NASA Apollo nine astronaut rusty Schweigert space station astronaut Ed -- And modified rocket scientist Scott harbored have become. The asteroid hunters launching their own mission to find asteroid that are on a collision course with our world. This -- it is important because. It's a wake up call that we should be looking out there these things -- hit -- -- The last near disaster was averted by pure luck it was 190 wait and a huge asteroid created direct hit. Fortunately into the -- dusk as Siberia. For a thousand miles of trees and wildlife were decimated. Just imaginable -- Chicago. But -- very large asteroid I'm talking about something -- miles cross. Then it would probably create the same kind of disaster that wiped out the dinosaurs. Amazingly no one -- -- Yee fourteen was headed our way. Until a Spanish dentist and amateur astronomer were randomly discovered this grainy proof a year ago. Of all of the asteroids that are out there that come near the earth and -- can do harm if they -- -- -- We only know 1% now. 99%. Of them we don't even know where they York. As anyone who's he Star Wars knows calculating the odds of getting hit by an asteroid is no small task. Can successfully navigating an asteroid -- approximately 3720. -- tell -- beyond. -- after this -- actually hit the year. In a typical person's -- and let's just say your lifetime. But about a one -- three when -- fortunate so the point here -- put this twice. And if I got heads twice. -- and there's another heads sorry we got smacked. The asteroid hunters are raising money to launch -- -- own asteroid early warning system called. Sentinel a dedicated in for -- space telescope scanning the starters -- threats. So what if they find one on a collision course then what the movie Armageddon had an idea. They're been lots of movies of course. -- they are -- send Bruce Willis. And though will blow it up with a why don't we just under a 150 nuclear warheads and blacks that and that is the wrong answer never get your physician on. You only need to change the velocity of an -- by something like a millimeter per second so to give an example that's about the speed that it can't crawl. The team says the solution is to run into a large asteroid or forget it with a space ship they call -- space tractor just to give it a little knowledge. It's pretty big thinking for what seems like -- off far out problem. But when you've seen our planet from space. You apparently look at things in a completely different light when you look at the earth from space and you begin to identify not just with -- your country or your continent. But with the whole earth you realize that this is such a precious place. It's not science fiction these men believe their work is necessary. To protect all of us. I'm Neal Karlinsky for Nightline. In Seattle.

This transcript has been automatically generated and may not be 100% accurate.

First Pictures of Approaching Asteroid

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Asteroid Makes Closest Pass Today

Asteroid, discovered by an amateur, will pass within 17,200 miles.

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